PROJECT SUMMARY Testing pharmacotherapies in controlled human alcohol laboratory paradigms is critical for the identification and development of therapeutic interventions to prevent alcohol use disorder (AUD). Thus, for this proposal, an alcohol administration procedure will be adopted in non-treatment-seeking individuals with AUD to establish the safety and tolerability of probenecid as a novel pharmacotherapy. This is a developmental/exploratory clinical trial that aims to test the hypothesis that proposes a potential relationship between the pannexin 1 channel and alcohol. The goal of this proposal is to evaluate the safety and tolerability of potential new therapeutic targets for the treatment of AUD. The premise prompting this human laboratory study is based on the direct evidence from our preliminary work with probenecid in a preclinical model of AUD. This work demonstrated that probenecid is able to reduce alcohol consumption in alcohol-dependent rats. The scientific rationale for testing probenecid in AUD was derived by the well-known mechanism of action of probenecid as a pannexin 1 channel inhibitor, its role in alcohol-induced extracellular adenosine release, and that this process is promoted by a history of exposure to excessive alcohol. In a controlled human alcohol laboratory setting, we will use behavioral and neuropsychopharmacological approaches to establish the safety and tolerability of probenecid administered with alcohol (Aim 1). In our secondary aims, we will test the hypotheses that treatment with probenecid will diminish alcohol's stimulant effect (Aim 2) and alcohol tolerance (Aim 3). In these aims, targeted pharmacological manipulation of probenecid with alcohol will be employed to evaluate the safety and tolerability of probenecid when administered with alcohol. We included craving and subjective preference measures as exploratory aims to inform a future larger trial. The proposed research is significant because, using pharmacological probes, it will provide a much-needed insight into the fundamental neurobiological mechanisms underlying alcohol biobehavioral effects with the goal of improving the therapeutic outcomes for individuals with AUD.